Matt weighs 60kg and his son, Rob weighs 30kg. They both run a 100m race and finish the race running at 5m/s. Who has more Kinetic Energy at the end of the race?

Kinetic energy is given by the equation:K.E. = 0.5mv²Therefore Matt has Kinetic energy:K.E. (Matt) = 0.5*(60)(5)² = 750JAnd Rob has Kinetic energy:K.E. (Rob) = 0.5(30)*(5)² = 375JTherefore Matt has the higher Kinetic Energy.(This can also be seen from observing that Matt is twice as heavy so will have twice as much Kinetic Energy)